Previously, micro methods for identifying or detecting biologically active materials involved the use of small test tubes, capillary tubes, trays and the like. The media utilized in these methods have previously been confined to liquid broths or agar gels which are prepared from commercially available powder forms. Problems inherently associated with media in the aforementioned forms are manifested in the labor of preparation, sterilization and dispersion which result in a material which lacks a commercially practical shelf-life. Macro methods involve the use of larger containers and have the same problems as associated with the micro methods.